A telescopic boom is oftentimes employed on cranes and other types of construction vehicles to dispose a work tool, mounted forwardly on the boom, at extended positions around the crane. The boom is comprised of telescopic sections which are extended and retracted relative to each other by one or more hydraulic cylinders. When the boom comprises three or more such sections, it has proven difficult to integrate the cylinders into the boom to permit relative and precisely controlled extension of the sections.